Many submersible vehicles, such as military submarines, include one or more object ejection systems. An object ejection system may be used to eject various types of objects from the vehicle. Such objects may include, for example, sonar buoys, counter measure devices, and various types of weapons, such as torpedoes and/or missiles. A typical object ejection system that is used to eject weapons from a submersible vehicle includes one or more weapon ejection tubes, an impulse tank, a boost pump, and an air turbine.
A weapon may be launched from an ejection tube by fluidly communicating the ejection tube with an impulse tank by, for example, opening a slide valve on the ejection tube, and then pressurizing the impulse tank with fluid. In many ejection systems the impulse tank is pressurized by commanding a firing valve to the open position, which allows high pressure air to flow to the air turbine. The air turbine, upon receiving the flow of high pressure air, drives the boost pump, which draws fluid (e.g., seawater) from the environment surrounding the vehicle hull and discharges the fluid, at a higher pressure, into the impulse tank.
Although the ejection system described above is generally safe, reliable, and robust, it does suffer certain drawbacks. For example, the system includes numerous components, such as one or more high pressure air storage tanks, the firing valve, and the interconnecting piping. These components take up space within a submersible vehicle hull, and add to the overall vehicle weight. Moreover, because operation with a relatively quiet acoustic signature may be desirable, these components can be relatively costly to design, produce, and install, and can exhibit relatively high maintenance frequencies. One proposed solution to these drawbacks has been to use an electric motor to drive the boost pump. However, the size of the electric motor that is needed to meet system functional requirements can be relatively large and costly.
Hence, there is a need for an object ejection system that may be implemented with relatively fewer components than present pneumatic systems and/or takes up less space and/or reduces overall vehicle weight and/or is less relatively costly to design, produce, and install and/or has relatively low maintenance frequencies. The present invention addresses one or more of these needs.